[Early detection of diseases of the circulatory system in vocational school students with particular reference to the prevention of coronary disease and arterial hypertension].

A group of 201 boys of vocational schools living in an area of developing industry (Bełchatów) and another area of developed industry (Lódź) were examined twice: at the age of 16-17 (I examination) and 14-18 months later (II examination). Incomplete right bundle-branch block and intraventricular conduction impairment have been demonstrated mainly in the resting ECG tracings (Table I). The risk factors of coronary heart disease were increasing with age, especially in boys of Bełchatów area (Table II). Five boys with risk factors of coronary heart disease exhibited ischaemic type of postexertional ST segment changes (Table III).